Method of building and launching floating craft.



H. ALFSEN.

AND LAUNCHING lFLOATING CRAFT. APPLICATmN FILED MAY10.19|7.

METHOD 0F BUILDING 1,258, 1 75. Patented Mar. 5, 1918.

yHARALD ALFSEN, OF PORSGRUND, NORWAY.

MF-'rtro'n--or :BUILDING AND LAUNCHING FLOATING CRAFT.

Specification of Letters Patent.

Patented Mar. 5, 1918.

Application ledMay y 1917. Serial No. 167,722.

Y '0 mit lf1/1,0m t may concern.'

le it lrnown that l? HARALD Ann/SEN, n

l subject. of the King of Norway.Y residing at Porsgrund, Norwny, haveinvented certain 'new and useful Improvements in Methods of BuildingandLaunching F losting Craft; and l do hereby declare the following tobe a tulh clear, and erect description of the in tuition, such willenable others skilled in the nrt to which it appertaiins to malte anduse 'the saine, reference being had to the accompanying drawings,A undto letter@v or .figures of reference marked thereon, which torni n partof this specification.

The present invention relates to the building and launching-of all kindsof floating craft such us ships, lighters, berges, pontoons und the likeand more particularly of such craft manufactured of concrete orreinhirecdv concrete.

In the ordinary way craft of this type are enst in nn upright positionbetween suitable lnthings ortorms, and launched as an ordinary ship. Thecasting of ionting craft in this way is however." n, costly anddiflicult as it becomes necessary to provide lething or forms bothinside and le the hull, and this again makes it lt to place the'reinforcement and keep the sinne in position during the castingoperations These' ditliculties are obvinted if the craftis cest iu. eninverted position with the bottoni up on an interior lsthing or formforming :i permanent but easily dismountable structure.

it has previously been proposed to cast similiar craft of concrete in:in inverted position in plaster-molds, but the method has been given.up as unpracticable owin to the dilticuities Aof turning over the cratafter the casting without injuring the same.

According to the present invention all the difficulties of turning overthe craft are obviated by launching the same in its inverted.

osition and turning vthe craft over after enriching.`

l In order to carry ont method in the best possible way., thedisplacement of the boat when filled withwater is so ypropor-v tioned tothe total weight of the. same that it will just be awash when the nirinside the hull has been dis laced by water.

The rightcon tions muy be obtained by regulating the volume of theinside lathing or forms that are launched with the bont so that itsbuoyancy is just suihcient to carry the concrete hull, or a number ofairtight compartments may be conveniently placed in the craft.

Air outlets are provided in the bottom of.

the hull. The deck may be cast after the boat has been launched or itmaybe cast together with the rest of the hull.

On the drawings:

Figure l is e cross section through aI 'bont and its lathings or formbefore thelaunching.

Fig 2 is a longitudinal section on a smaller scale.l

Figs. 3 to 7 show cross sections of the boat after the launching and ondiierent stages of the turning over process.

1 is the huiI 2 and 3 the outside and in side lathing or formsrespectively and 4 is the yplatform on which the boat is built. Aiutightcompartments or cells 5 are provided on each side of the hull and airout- .lets 6 in the bottom of the same in the open portion of the formto which Water is to be admitted.

It will be noted that the outside lathing only extends alon the verticalsides of the boat' while the hul is cast or plasteredA on the interiorlathing only. The latter ma consist of large boards or sections which ttogether to form a definite structure and may be easil taken apart foruse in custing new ships o the same type.

After the ship has been launched it will firstloat in the position shownon Fi 3, but as the air is let out through the ho es 6 in the bottom anddisplaced by water, it will sink till it arrives in the position shownon Fig. 4 in which the ships weight is equal#l ized by its buoyancy.

As the airtight compartments in this osition are in the lowest part ofthe s i while the heavy bottom is at the top,it 1s levidentlthat itsequilibrium will be instable ioutin above the water line so that thewater may be pumped out after the launching operai` lforms, launchingthe structure with its con tained forms upside-down :is constructed,rightingthe craft and removing the forms. '2. The method of building andlaunching craft which comprises constructing the hu upsidcdown u onmeans capable of fionting the hull, laune ing the structure in itsupside-down position, rghting the hull and removin the fioatin means.

3. The met od of'buil ing und, launching loatin craft which comprisescolistrmzting the hu l upside-down upon a suitcblc form of suilicient4buoym'icy to cause thc conter of gravity to lie above the center ofbuoyancy of the combined hul-l and form7 lnuuchin y the craft in anupsidcilown position un. righting the hull while afloat and removing theform. A l

4. The method of building and launching floating craft which comprisesconstructing the hull upsidedown upon suitable ormsin which internalaipti ht cells and, open cells -are rovided, launching the hull undforms in t eir u sidedown. .ositiom venting the air from tie open oei s,:righting the hull, and removin the forms.

f r5. The met lod of buildinand munching, in, costing thc' concretevessels Whicl. consi hull yupside down, on :in interior framework inwhich airtight cells and an open. cell are provided, the castingbeingrprovided with e non-return valve allowing air to escupe from the opencell, but preventin water from. eu-v terin `the same and laune ing saidvessel upsi e down `as cast, wherebv the same ussumes f' osition ofunstable equilifbrium, rights itse f, and remains afloat. Y

6. The method o! building and launching fioatin ycraft which comprisesbuilding the hull o reinforced concrete upside `down on suitahleinteriorbuo mit forms, launching the hull, with the therein, "upside-v meeuwdown und removing the nir from the invcrted hull, the buoyancy ci scidforms beM ing proportioned to keep the hull nvvush ufterthe 1'" l ci* te nii:n righting the tl' tori. s. lnnlding und launching comprisesconstructing s buiiiycnt in, ,l form for he craft proportioned to i iinthe com ed. hull und form .in unstable iin" ting equi .i .i structingth, ull ilo-down of reinforced concrete won s id torni.y launching the'bull upside-down. wit die forni therein, venting oir from the hull,righting the hull und ney movin y the form. y 8 lic method ci" buildingund launching Hosting @mit which. compri' s constru ting an interiorbuoynnt form ha' ing cir-tight compartments und open cells constructingthe hull. bottom up of miniorciiad concrete ou scid forni, lnuu becombined hull und form1 ven cells, rightin Writer und f' nmintcin thlcuncl'icd in libriui to f floating* ci or unstubc equiing of tin hull.c ding and launching limiting rises iiiuilding a forro. lievi g :tir-tghi; cls und open oeils, constructing the huii inisid-e-dowii on. suchform, munching the combined hull. und form, t d :form constructed toposition the .iya cy below theccnter of grav ic hull and .Ecrinm ventingthe huit, und rerumTM 'i i of buil iing und inuuching lich, ci' )risesbuilt ng" un i1 i htcolic and o ien i hull upsnfio .c ng; thc combinedvv. ting the cir ght relis of down r i hull. incl y hc ucriuicnini huilund the structure tc riglit itself und com mt.

In t n inv thct i 'i the feic'egoing as i. nvcntion, I have gncd my namein pc of tivo snhscrl' itncsses. i

QD ALFSTJN. 'Witnesses c i Vomiting,

un ln LEE;

